Trump says migrants should be ‘stopped at border.’ Meanwhile, thousands enter Canada from U.S.

U.S. President Donald Trump took to Twitter Monday to criticize the country’s process for dealing with migrants.

He suggested that the entire system needs to be honed down to one step — refusing entry.

WATCH: President Donald Trump says he was “very, very happy” to sign executive order on immigration

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“People must simply be stopped at the Border and told they cannot come into the U.S. illegally. Children brought back to their country……”

The Trump administration has faced international criticism over its “zero tolerance” immigration policy, which led to thousands of children being separated from their parents at the U.S.-Mexico border.

READ MORE: Detained migrant tells story of last time she saw her son

Human rights violations

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The problem with Trump’s suggestion is that refusing migrants altogether goes against international law, said Craig Damian Smith, who works with the Global Migration Lab at University of Toronto’s Munk School of Global Affairs.

“In terms of international law, in terms of international human rights law and international refugee law, people who present themselves at a border and ask for asylum are to be given access to asylum processing,” Smith told Global News.

WATCH: Trump hails Mexico’s immigration processing better than the U.S.

1:00 Trump hails Mexico’s immigration processing better than the U.S.

The U.S. signed on to the United Nation’s 1951 Refugee Convention, which stipulates those rules, he explained.

One of the main rules is that you can’t push people back into a dangerous situation, Smith added, noting that’s exactly what the U.S. would be doing if it refuses all irregular migrants without assessing their claims.

Refusing entry into Canada?

Refusing entry also brings into question the thousands of asylum seekers who have entered Canada through the U.S. border in the past months.

More than 7,600 people crossed the Canada-U.S. border illegally between Jan. 1 and April 30.

Canada does not refuse entry to those individuals and offers them a chance to claim asylum.

READ MORE: Here’s how Canada deals with migrant parents, children and detention

The federal Opposition has urged the Trudeau government to take another look at those rules. They have specifically pushed the Liberals to update the Safe Third Country Agreement with the U.S., which allows either country to turn back asylum seekers who enter at a formal Canada-U.S. border crossing.

The Opposition has urged that agreement be broadened to apply to the entire border.

Smith explained expanding the provision could lead to more problems — RCMP would have to be stationed across the entire border, and there would likely be a rise in refugee arrests.

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“If you say our whole border is closed and asylum seekers can’t come through — even if it’s dangerous for you in the U.S. — then the outcome of that is you would create the market incentive for human smugglers,” Smith added.

It would also lead to international criticism and damage Canada’s reputation on human rights.

“The short answer is that it wouldn’t work,” Smith said.

Tweet This Click to share quote on Twitter: "The short answer is that it wouldn't work," Smith said.

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Public Safety Minister Ralph Goodale has dismissed reports that Canada is looking to expand how much of the border is included in the deal, but said the government may ask U.S. officials to take part in “exploratory” talks about the agreement.

“It’s a discussion we’re having with the Americans about the various techniques that could be pursued on both sides of the border to ensure security and integrity,” Goodale said in May.

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Meanwhile, immigration advocates have urged Canada completely end the agreement with the U.S., saying it is no longer a safe country for migrants under the Trump administration.

An online petition from the Ottawa-based Broadbent Institute is calling on Canada to end the agreement, and has nearly 7,000 signatures so far.

“Canada has a legal and moral responsibility to provide asylum to those who seek it — including migrants at the Canada/U.S. border,” the petition reads. “Given the deteriorating situation in the U.S., we need to act immediately.”

— With a file from The Canadian Press